In the upgrading of olefins or the conversion of one or more olefins to a more desirable olefin or mixture of olefins, it frequently has been necessary to treat the olefins for both double bond isomerization and disproportionation in order to obtain the desired product or product mixtures.
In the past, most such operations have involved a two stage sequential treatment process employing a catalyst active for double bond isomerization in one step, and another catalyst active for disproportionation of olefins in a separate step.
Some single stage processes have been attempted, employing a physical mixture of catalysts, one of which is active for double bond isomerization and the other active for disproportionation. Even with homogenity improved by grinding or by ball-milling, such mixtures have not proven fully satisfactory in uniformity and control of the reaction. Frequently, one aspect of the mixed catalyst will prefer one set of reaction conditions, and the other aspect of such a mixture will prefer a different set of reaction conditions. The active conditions imposed sometimes are an unhappy compromise unsatisfactory to either.
Needed has been a single catalyst composition that will function effectively in both aspects, double bond isomerization, and disproportionation, in a single stage operation.